Engine valve control means

ABSTRACT

An engine valve operating control mechanism for an internal combustion engine having a transmission output driven gear pump and governor controlling the output of the oil pressure from the pump in direct proportion to the engine load whereby a hydraulic cylinder and piston unit operated by the pump pivots a camshifting lever which shifts the camshaft to move one of three different contoured cam lobe means in contact with the engine valves for opening and closing the intake and exhaust valves at one of three operating conditions for low, medium or high engine speed operation under load conditions.

Unite States atom 51 3,638,624

OGrady 1 Feb. 1, 1972 [54] ENGINE VALVE CONTROL MEANS 1,863,875 6/1932 Rabezzana ..123/90.18

[72] Inventor: Donald J. OGrady, 7634 W. Clarence Ave., Chicago, 111. 60631 [22] Filed: Apr. 13, 1970 [21] Appl.No.: 27,658

Primary Examiner-Al Lawrence Smith Attorney-Richard J. Myers [57] ABSTRACT An engine valve operating control mechanism for an internal combustion engine having a transmission output driven gear 31c 31b 31a [52] US. Cl ..123/90.l8 pump and governor controlling the output of the oil pressure [51] Int. Cl "F011 7/34, F011 1/08 from the pump in direct proportion to the engine load [58] Field of Search ..123/90.17, 90.18, 90.15 whereby a hydraulic cylinder and piston unit operated by the pump pivots a cam-shifting lever which shifts the camshaft to 5 References Cited move one of three different contoured cam lobe means in contact with the engine valves for opening and closing the intake UNITED STATES PATENTS and exhaust valves at one of three operating conditions for 2,804,061 8/1957 Gamble ..123/9o.1s gigggf engme Speed operam under mad 2,528,983 11/1950 Weiss ..l23/90.l8 X 2,682,260 6/1954 Lantz ..l23/90. 17 12 Claims, 5 Drawing Figures JO 3 Jia.

\ g Or 6 X E S ya A 24250 16a 25 J v a 7 2 i9 i J9 21b 21 20 J6 J3 6 PATENTEO FEB 1972 3 ,'53 ;5

ENGINE VALVE CONTROL MEANS SUMMARY This invention relates to internal combustion engines and in particular to regulation of the air and gas intake and exhaust valve operation of the engine in accordance with engine load.

It is known in the art of internal combustion engines that as the speed of the engine increases, in order to have more efficient combustion of the gases, it is desirable to increase the time the intake and exhaust valves are held open. Ordinarily, the engine intake valves are operated by cams fixed upon camshaft so that the valves remain open over a fixed period, expressed in degrees of camshaft rotation, whether the engine is traveling at a high or low speed. It will be seen, therefore, that when the engine is traveling at a high speed or a relatively high rpm. the valves will remain open a shorter time measured in seconds or fractions of a second although they are held open for the same period expressed in degrees of rotation of the cam. As the camshaft rotates at a greater speed when the engine operates at a higher speed, the shaft will rotate in a much shorter time through the arc during which the cam acts upon the valve tappet and thus valves will be held open over a shorter period measured in seconds than when the engine is operating at a relatively low rpm. The higher the engine speed the greater will be the demand for fuel and since the valves are open such a relatively shorter time the valve openings then act to throttle or restrict the fuel-airflow to the cylinder of the engine, thus inhibiting full accommodation of the cylinder vacuum. This will, of course, not only limit the speed of the engine, but, as a relatively small charge is drawn into the cylinder at each opening of the valve, the designed compression ratio is not obtained on the compression stroke of the piston when such a starved condition exists. Standard stock cars are provided with a cam of such shape that it is a compromise between the optimum for the lowest and the highest speeds of the engine. In racing cars the cams are so made as to hold the valves open a longer time than in stock cars and thus the valve-actuating mechanism of a racing car is not suitable for slow speeds. Today with the wide speed ranges and the popularity of high-compression engine it is desirable to have a better relation between the time valves are open and the speed of the engine.

A general object of this invention is to provide new and improved means for actuating the engine valves of an internal combustion engine at different engine speeds.

Another object of this invention is to provide for a variable cam lobe arrangement for an engine where the cam lobe arrangement is regulated by means responsive to the output load of the engine.

Still another object of this invention is to provide for an engine valve operating mechanism for an internal combustion engine using a multilobed cam arrangement which is shiftable in accordance with engine load to open the engine valves longer at high speeds wherein an output speed member operates a governor which controls the flow of pump delivered pressurized hydraulic fluid to a hydraulic unit mov ing through linkage the camshaft and cam lobe arrangement.

Another object of this invention is to provide a valve-actuating arrangement that is operative upon both intake and exhaust valves.

A further object of the invention is to provide for a mu]- tilobed cam arrangement for operating engine valving, the cam arrangement being operated by a novel valve opening control means.

To these and other ends the invention consists in the novel features and combinations of parts to be hereinafter described and claimed.

BRIEF DESCRIPTION OF THE DRAWING FIG. I is a cross-sectional view of an internal combustion engine;

FIG. 2 is a longitudinal view of the novel mechanism operativc upon the intake and exhaust valves of the engine for varying the time of the valve opening in accordance with the load on the engine;

FIG. 3a is a sectional view taken along line 3a3a of FIG. 2;

FIG. 3b is a sectional view taken along line 3b-3b of FIG. 2; and

FIG. 30 is a sectional view taken along line 3c-3c of FIG. 2.

DETAILED DESCRIPTION With reference to the drawings and in particular to FIG. 1, there is shown an internal combustion engine 2 having a head 3 and a block 4 from which depends pan 4a. In the block 4 is the piston 5 received in the cylinder 6 housing the combustion chamber 60, the piston rod 7 connecting the piston with the crankshaft 8. The piston, in conjunction with other pistons not shown, drives the crankshaft 8 upon ignition of the spark plug 9 in the combustion chamber. The exhaust valve 10 allowsfor escape of the burned gases and is operated by a valve stem 11 having a valve head 11b resting on valve seat 11a in the closed position of the valve. A spring-loaded lifter arrangement 12 having a lifter body 13 is driven by cam means 14 on the camshaft 15.

As best seen in FIG. 2, there is shown a portion of the output shaft or tail shaft means of the vehicle transmission (not shown) which is driven by the engine 2. The tail shaft portion 16a connects with shaft portion 16b for driving the gears 26b and 26a of the gear pump 26 and the tail shaft 16a also connects with the governor shaft 17a by gears G and G for driving the governor 17. The cooperative action of the governor and the gear pump causes the movement of the hydraulic unit 31. The camshaft operating means 16 comprises the governor 17, the gear pump 26, reservoir 27 and the hydraulic unit 31. It is seen that the oil gear pump 26 and the governor which are both driven from the tail shaft of the transmission at or near the vehicle speedometer gear, control the flow and pressure of oil to the hydraulic actuating means or the hydraulic to mechanical lever power converter or unit 31. The actual amount of flow of oil is governed by the position of the governor piston 21a which is controlled by the forward speed of the vehicle. The governor comprises the input shaft 17a, the governor arms 19 and the governor return spring 17b and the governor weights 18, the arm means 19 being connected to the governor output shaft or metering rod 20 which is provided with the metering piston 21a at its inner end slidable in metering cylinder or housing 21b restricting the flow of oil from the gear pump 26 via passage 25 into the metering chamber 23a and out into the conduit 24 to the hydraulic actuating unit 31. From reference to FIG. 2, it is readily seen that as the speed of the vehicle increases (piston 21a in dotted position at right and weights 18 in far out dotted line position and valves being operated by high-speed cam portions 48), the speed of the tail shaft increases and causes the governor weights 18 to fly outward and move the metering rod 20 to the right to permit increased flow of fluid from the gear pump to the conduit 24. The pressure in line 24 and the cylinder 31a increases with increase in the speed of the pump due to increased vehicle speed and vice versa. As the vehicle speed increases, fluid flow increases but as the speed decreases it is seen that a restriction is developed at passage 25 by movement of the piston 21a to the left and, therefore, the flow is decreased. Consequently, as the piston 21a moves to the left (as seen where piston 21a and weights 18 are in solid line position with the valves being operated by middle-speed cam portions 46), the hydraulic piston 31b of the hydraulic unit 31 is permitted to move to the right for movement of the converter outlet rod or arm 32 to the right; whereas when the flow is from passage 25 into the chamber 23a at low speed, fluid flows out passage 29 to reservoir from cylinder 31a and the pressure in the cylinder 310 against the piston 31b is reduced and the return spring 31d in cylinder 31a pushes the piston 31c and consequently rod 32 further to the right. The fly weights 18 are in the most inner dotted line position and piston 21a is at left dotted line position and valves are operated by low-speed cam portions 44.

The converter outlet rod or arm 32 is constrained for movement, of course, with the hydraulic actuating unit piston stem 31c and the outer end of the shaft 32 includes a threaded extension 33b and an adjusting nut 33a that act as a connector arm adjuster 33 for adjustably affecting the overall effective length of the converter outlet rod 32 as desired for different engines. The left end of the adjuster rod 33b is pivotally connected by pivot means 34a to the camshaft shifting lever 34 which is pivotally connected and fulcrumed at pivot connection 35a to the support 35 mounted onto the vehicle engine wall 36a. The engine wall above the lever support 35 is provided with a roller bearing means 40 which journals the left end of the camshaft l and a compression spring 39 is provided about the camshaft between the bearing means 40 and the lever mounting and connection structure to which the camshaft shift lever 34 is connected for movement of the camshaft l5 reciprocally along its longitudinal axis. An end cap 15a supports the end of shaft 15 in its bearing portion 15b which has its bore reciprocally support the camshaft therein. The upper end of the shifting lever 34 is a U-shaped fork 34a which is entrapped between the lands or projections 38b of the outer rotatable bearing race 38: of the bearing structure 38a and engages this race 380 to shift the shaft 15 either to the right or left as seen in FIG. 2, the outer race 38c rotating on roller bearings 38d, the inner race 38:: being fixed or immovable on the shaft 15. Intermediate the lever mounting and connection structure 38a and the exhaust valve cam means 14 is provided intermediate camshaft journal or roller bearing 41. The variable cam-lobed means 14 is engageable with the lifting body 13 of the exhaust valve for operation thereof as aforesaid. To the right of the cam means 14 and also fixed on shaft is cam-lobed means 14a engageable with the lifter body 13 of the intake valve 50 for operation thereof in the manner that the exhaust valve is opened and closed. The construction and arrangement of the exhaust valve and its cam means is identical to the construction of the intake valve and its cam means. To the right of the intake cam valve means 14a there is provided another end camshaft journal or bearing arrangement 54 to the right of which is provided the splined camshaft end portion 55 extendable into the splined housing 56. The bearings 40, 41 and 54 have the same outer diameter which is of sufficient dimension to permit withdrawal of the entire camshaft and cam means from within the engine for easy removal of the camshaft and cam means without a major disassembly task being performed. The compression spring 57 in the housing 56 abuts against the end of the splined camshaft portion 55 and the splined timing gear hub 58. The hub 58 is attached to the front engine block wall 59 which carries the roller bearing or end bearing 60 which is entrained by the bearing and hub retainer member having hat-shaped plate 61a and bolt means 61b tying the hat-shaped plates to the wall 59. The timing gear shaft 62 which is attached and constrained for movement with the hub and the housing 56 carries, at its right end, timing gear 63 which is of conventional structure and rotates the camshaft in accordance with engine speed and demands in the usual manner.

The shifting of the camshaft 15 in accordance with engine speed shift the cam means 14 and 14a for controlling the duration that the exhaust and intake valves are held open. In FIGS. 3c, 3b and 3a there is shown the sectional views of the exhaust valve cam means 15 showing the low-, mediumand highspeed lobes 44, 46 and 48 respectively. The intake cam means is also provided with low-, mediumand high-speed cam lobes 51, 52 and 53 which are identical to lobes 44, 46 and 48 respectively. It is noted that in FIG. 3c, the low-speed lobe is contoured for a faster closing than the high-speed cam lobe 48 of FIG. 3a and, of course, the intermediate lobe 46 of FIG. 3b provides for a compromise valve open-to-close time between the lowand high-speed lobes 44 and 48. In this respect it will be noted that the low-speed lobe 44 is more tapered and pointed at its upper end and the intermediate lobe 46 is less pointed and whereas the fast opening and closing valve lobe 48 is definitely more circular on its upper end portion. These lobes 44, 46 and 48 are integral with one another as are lobes 51, 52 and 53.

In operation it is seen that the pump 26 and governor 17 control the actual flow of the oil to the actuating hydraulic unit cylinder 31a. The piston 21b restricts oil flow from the pump 26, and from the cylinder 31a at middle engine speeds and middle engine loads as seen in the solid line position of the components in FIG. 2, and the chamber 23a is able to drain to reservoir 27 by way of line 29 at low-engine speeds and loads. At high-engine speeds and loads full pump pressure and flow is sent to the cylinder 31a, relief valve means 26c dumping to reservoir on overloading. The amount of oil sent to the cylinder 31a depends upon the speed of the vehicle. Where an automatic transmission is used, the automatic transmission oil can be used and the reservoir can be eliminated and it is also possible to use the automatic transmission governor. As the vehicle speed increases, more oil is sent. As the vehicle speed is decreased, less oil is sent. The oil is circulated from the reservoir 27 through inlet port 28 and into the pump 26 where it passes between gears 26a and 26b, the latter which is driven by the gear input shaft 16b and the oil flows from the gears through the pump outlet passage 25 and into the chamber 23a. The pump is provided with said pressure relief valve and port means 26c to reservoir should excessive pressures develop in the pump. The hydraulic unit 31 causes movement of the camshaft shifting lever 34 to which it is attached and the lever moves the camshaft l5 forward or to the right (see FIG. 2), the amount of forward movement depending upon the oil pressure in the actuating cylinder to overcome the compression centering springs 39 and 57. When the camshaft moves forward, the length of time the valves are held open is changed. The valves are held open longer the more forward the camshaft moves. This is accomplished by the variable cam lobes 44, 46 and 48 of the exhaust valve 14 and 51, 52 and 53 of the intake valve 14a. When the vehicle speed decreases, the governor speed decreases allowing less oil to flow into the cylinder 31a decreasing the pressure against the actuating piston 31b and allowing the compression spring 31d to move piston 31!; to the right and the camshaft 15 back toward the left until at low speed or idle, very low or zero pressure in the actuating cylinder 3111 allows the camshaft spring 57 to move the camshaft back the full amount (all the way to the left, FIG. 2) for best idle speed. The governor 17 allows the oil to pass from the chamber 23a via line 29 to the reservoir 27 which is provided with line 30 to atmosphere. By being able to move the camshaft back and forth in relation to the vehicle speed, we can make the engine more efficient because we can change the timing cycle of the valves by means of these variable cam lobes keeping the valves open longer at higher vehicle Speeds and closing the valves sooner at lower vehicle speeds and idle. The cam lobe 44 is operative at idle and low speeds up to 20 miles an hour; whereas the cam lobe 46 is operative at intermediate speeds beyond 20 miles per hour up to 50 miles per hour, and the high-speed lobe 48 is operative at speeds in excess of 50 miles per hour.

Being monitored from the tail shaft 163 of the transmission, the variable cam lobe system will operate only when the vehicle is in motion. Therefore, there is no overspeeding of the engine without a load being applied which could, if permitted, cause the engine to reach revolutions per minute far above safe limits and this could cause complete destruction of the engine or bodily harm to the operator of the vehicle, its passengers or anyone in the proximity of the vehicle. Adjustment of the fore-and-aft movement of the camshaft for initial setup to compromise for wear or best performance is easily made by adjusting the adjusting means 33 of the actuating cylinder 31 which is located outside of the engine under the vehicle hood. The three roller bearing means 40, 41 and 54 used on the camshaft create friction points and subject the parts to wear and these parts are easily lubricated from the standard engine oil pump and oil system. As aforesaid, the camshaft may be removed from the engine in a normal manner with no extra work or parts to be removed. The camshaft timing gear does not move for-and-aft with this system. Further, there is not abnormal wear or strain on the timing gear. If, for any reason, the variable cam lobe system means of changing the camshaft should fail due to loss of oil pressure, governor inoperativeness, system gear pump inoperativeness, or a broken camshaft shifting lever, etc., the cam lobe system would be fail-safe, as the camshaft could be driven in the low-speed driving range or means of adjustment on the hydraulic cylinder could be used to move the camshaft to midspeed driving range and drive the camshaft as a nonvariable camshaft means.

The foregoing description and drawings merely explain and illustrate the invention and the invention is not limited thereto, except insofar as the appended claims are so limited, as those skilled in the art who have the disclosure before them will be able to make modifications and variations therein without departing from the scope of the invention.

lclaim:

1. In a vehicle including an internal combustion engine having cam operated valve means, means for increasing the length of time the valve means are open in accordance with increasing of the speed of the vehicle comprising:

variable cam lobe means adapted for engagement with said valve means and inclu;ing a low-speed cam lobe, an intermediate-speed cam lobe and a high-speed cam lobe,

a longitudinally reciprocally shiftable valve camshaft carrying said variable cam lobe means,

linkage means connecting with said camshaft for shifting same,

vehicle output speed means,

fluid motor means connecting with said linkage means and operable to act thereupon attendant to shifting of said camshaft,

fluid supply means operatively connected with said fluid motor means for delivery of fluid thereto,

said fluid supply means being a reservoir and pump means communicating with the reservoir and delivering fluid to the fluid motor means, the volume of fluid increasing in the fluid motor means in accordance with increase in vehicle speed,

said fluid supply means and said fluid motor means communicating with said reservoir,

regulating means operatively connected with the fluid motor means and being operatively connected with the vehicle output speed means for affecting the supply of fluid to the fluid motor means in accordance with the speed of the associated vehicle output speed means,

said regulating means including a metering chamber communicating with said fluid supply means and with said fluid motor means and having a metering valve in said metering chamber defining a restriction for restricting the flow of fluid between the fluid motor means and said pump means during the engagement of the intermediatespeed cam lobe with the engine valve means, said restriction decreasing with increasing vehicle output speed and vice versa, said metering valve permitting relatively unrestricted fluid communication between the pump means and the fluid motor means during engagement of the high-speed cam lobe with the engine valve means and said metering valve blocking fluid communication between said pump means and said fluid motor means during engagement of the low-speed cam lobe with the engine valve means, and

said pump means having pressure relief valve means for dumping excess pressurized fluid to the reservoir upon increased fluid pressure when the engine valve means engages in the intermediate-speed cam lobe.

2. The invention according to claim 1, and

each of said lobes being integral with the other, said lowspeed cam lobe having a greater taper than the other lobes and said intermediate lobe having a portion with a lesser taper than the high-speed lobe and said high-speed lobe having a portion with a minimal taper relative to the other lobes.

3. The invention according to claim 1, and

said variable cam lobe means being contoured to hold open the engine valve means for a length of time that is generally directly proportional to the vehicle output speed.

4. The invention according to claim 1, and

said cam lobe means having a tapered portion having a decreasing taper contour in the direction of movement of the camshaft for increasing the length of time that the valve means are held open.

5. The invention according to claim 1, and

said linkage means including a camshaft shift lever pivotally mounted intermediate its end and having one end pivotally connected with the camshaft and having the other end pivotally connected with said fluid motor means.

6. The invention according to claim 1, and

said linkage means including a camshaft lever pivotally intermediate its end and having one end connecting with said camshaft, said linkage having an adjustable link means pivotally connected with said lever fixedly connected with said fluid motor means and reciprocal thereby.

7. The invention according to claim 1, and

said fluid motor means comprising a hydraulic cylinder and a piston reciprocally disposed within said cylinder and connecting with said linkage means, said piston and cylinder communicating with said fluid supply means whereby said piston is moved to enlarge the area within the cylinder upon increase in vehicle output speed and to decrease the area within the cylinder upon a decrease in vehicle output speed.

8. The invention according to claim 1, and

said regulating means including a governor means operatively connected with associated speed output means of the vehicle and valve means connecting therewith and with said fluid motor means and fluid supply means to provide a restriction between the fluid motor means and the fluid supply means, the size of the restriction increasing with decreasing vehicle speeds. 4

9. The invention according to claim 1 and said vehicle output speed means being connected with and operating said pump.

10. The invention according to claim 1, and

first biasing means urging said camshaft in a direction toward said fluid motor means and said fluid motor means having biasing means urging the fluid pressure in said fluid motor means toward said pump means.

11. The invention according to claim 5, and

means mounting said camshaft for reciprocal motion and including biasing means urging said camshaft in opposition to the fluid forces in said fluid motor means.

12. The invention according to claim 5, and

said camshaft having a splined end portion and a hollow splined seat receiving said splined end portion and supporting one end of said camshaft for reciprocal movement of said camshaft by said shift lever. 

1. In a vehicle including an internal combustion engine having cam-operated valve means, means for increasing the length of time the valve means are open in accordance with increasing of the speed of the vehicle comprising: variable cam lobe means adapted for engagement with said valve means and including a low-speed cam lobe, an intermediate-speed cam lobe and a high-speed cam lobe, a longitudinally reciprocally shiftable valve camshaft carrying said variable cam lobe means, linkage means conneCting with said camshaft for shifting same, vehicle output speed means, fluid motor means connecting with said linkage means and operable to act thereupon attendant to shifting of said camshaft, fluid supply means operatively connected with said fluid motor means for delivery of fluid thereto, said fluid supply means being a reservoir and pump means communicating with the reservoir and delivering fluid to the fluid motor means, the volume of fluid increasing in the fluid motor means in accordance with increase in vehicle speed, said fluid supply means and said fluid motor means communicating with said reservoir, regulating means operatively connected with the fluid motor means and being operatively connected with the vehicle output speed means for affecting the supply of fluid to the fluid motor means in accordance with the speed of the associated vehicle output speed means, said regulating means including a metering chamber communicating with said fluid supply means and with said fluid motor means and having a metering valve in said metering chamber defining a restriction for restricting the flow of fluid between the fluid motor means and said pump means during the engagement of the intermediate-speed cam lobe with the engine valve means, said restriction decreasing with increasing vehicle output speed and vice versa, said metering valve permitting relatively unrestricted fluid communication between the pump means and the fluid motor means during engagement of the high-speed cam lobe with the engine valve means and said metering valve blocking fluid communication between said pump means and said fluid motor means during engagement of the low-speed cam lobe with the engine valve means, and said pump means having pressure relief valve means for dumping excess pressurized fluid to the reservoir upon increased fluid pressure when the engine valve means engages in the intermediate-speed cam lobe.
 2. The invention according to claim 1, and each of said lobes being integral with the other, said low-speed cam lobe having a greater taper than the other lobes and said intermediate lobe having a portion with a lesser taper than the high-speed lobe and said high-speed lobe having a portion with a minimal taper relative to the other lobes.
 3. The invention according to claim 1, and said variable cam lobe means being contoured to hold open the engine valve means for a length of time that is generally directly proportional to the vehicle output speed.
 4. The invention according to claim 1, and said cam lobe means having a tapered portion having a decreasing taper contour in the direction of movement of the camshaft for increasing the length of time that the valve means are held open.
 5. The invention according to claim 1, and said linkage means including a camshaft shift lever pivotally mounted intermediate its end and having one end pivotally connected with the camshaft and having the other end pivotally connected with said fluid motor means.
 6. The invention according to claim 1, and said linkage means including a camshaft lever pivotally intermediate its end and having one end connecting with said camshaft, said linkage having an adjustable link means pivotally connected with said lever fixedly connected with said fluid motor means and reciprocal thereby.
 7. The invention according to claim 1, and said fluid motor means comprising a hydraulic cylinder and a piston reciprocally disposed within said cylinder and connecting with said linkage means, said piston and cylinder communicating with said fluid supply means whereby said piston is moved to enlarge the area within the cylinder upon increase in vehicle output speed and to decrease the area within the cylinder upon a decrease in vehicle output speed.
 8. The invention according to claim 1, and said regulating means including a governor means operatively connected with associated speed output means of the vehicle and valve means connecTing therewith and with said fluid motor means and fluid supply means to provide a restriction between the fluid motor means and the fluid supply means, the size of the restriction increasing with decreasing vehicle speeds.
 9. The invention according to claim 1 and said vehicle output speed means being connected with and operating said pump.
 10. The invention according to claim 1, and first biasing means urging said camshaft in a direction toward said fluid motor means and said fluid motor means having biasing means urging the fluid pressure in said fluid motor means toward said pump means.
 11. The invention according to claim 5, and means mounting said camshaft for reciprocal motion and including biasing means urging said camshaft in opposition to the fluid forces in said fluid motor means.
 12. The invention according to claim 5, and said camshaft having a splined end portion and a hollow splined seat receiving said splined end portion and supporting one end of said camshaft for reciprocal movement of said camshaft by said shift lever. 